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Lippe M, Szczepaniak U, Hou GL, Chakrabarty S, Ferreiro JJ, Chasovskikh E, Signorell R. Infrared Spectroscopy and Mass Spectrometry of CO2 Clusters during Nucleation and Growth. J Phys Chem A 2019; 123:2426-2437. [DOI: 10.1021/acs.jpca.9b01030] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Martina Lippe
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland
| | - Urszula Szczepaniak
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland
| | - Gao-Lei Hou
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland
| | - Satrajit Chakrabarty
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland
| | - Jorge J. Ferreiro
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland
| | - Egor Chasovskikh
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland
| | - Ruth Signorell
- Laboratory of Physical Chemistry, ETH Zürich, Vladimir-Prelog Weg 2, CH-8093 Zürich, Switzerland
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2
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Sode O, Cherry JN. Development of a Flexible-Monomer Two-Body Carbon Dioxide Potential and Its Application to Clusters up to (CO 2 ) 13. J Comput Chem 2017; 38:2763-2774. [PMID: 29067701 DOI: 10.1002/jcc.25053] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 07/28/2017] [Accepted: 08/03/2017] [Indexed: 12/20/2022]
Abstract
A flexible-monomer two-body potential energy function was developed that approaches the high level CCSD(T)/CBS potential energy surface (PES) of carbon dioxide (CO2 ) systems. This function was generated by fitting the electronic energies of unique CO2 monomers and dimers to permutationally invariant polynomials. More than 200,000 CO2 configurations were used to train the potential function. Comparisons of the PESs of six orientations of flexible CO2 dimers were evaluated to demonstrate the accuracy of the potential. Furthermore, the potential function was used to determine the minimum energy structures of CO2 clusters containing as many as 13 molecules. For isomers of (CO2 )3 , the potential demonstrated energetic agreement with the M06-2X functional and structural agreement of the B2PLYP-D functional at substantially reduced computational costs. A separate function, fit to MP2/aug-cc-pVDZ reference energies, was developed to directly compare the two-body potential to the ab initio MP2 level of theory. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Olaseni Sode
- Department of Chemistry, Biochemistry and Physics, The University of Tampa, Tampa, Florida, 33606
| | - Jasmine N Cherry
- Department of Chemistry, Biochemistry and Physics, The University of Tampa, Tampa, Florida, 33606
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3
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Georges R, Michaut X, Moudens A, Goubet M, Pirali O, Soulard P, Asselin P, Huet T, Roy P, Fournier M, Vigasin A. Nuclear Spin Symmetry Conservation in 1H 216O Investigated by Direct Absorption FTIR Spectroscopy of Water Vapor Cooled Down in Supersonic Expansion. J Phys Chem A 2017; 121:7455-7468. [PMID: 28914060 DOI: 10.1021/acs.jpca.7b06858] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the results of an experimental study related to the relaxation of the nuclear spin isomers of the water molecule in a supersonic expansion. Rovibrational lines of both ortho and para spin isomers were recorded in the spectral range of H2O stretching vibrations at around 3700 cm-1 using FTIR direct absorption. Water vapor seeded in argon, helium, or oxygen or in a mixture of oxygen and argon was expanded into vacuum through a slit nozzle. The water vapor partial pressure in the mixture varied over a wide range from 1.5 to 102.7 hPa, corresponding to a water molar fraction varying between 0.2 and 6.5%. Depending on expansion conditions, the effect of water vapor clustering was clearly seen in some of our measured spectra. The Boltzmann plot of the line intensities allowed the H2O rotational temperatures in the isentropic core and in the lateral shear layer probed zones of the planar expansion to be determined. The study of the OPR, i.e., the ratio of the ortho to para absorption line intensities as a function of Trot, did not reveal any signs of the OPR being relaxed to the sample temperature. In contrast, the OPR was always conserved according to the stagnation reservoir equilibrium temperature. The conservation of the OPR was found irrespective of whether water molecule clustering was pronounced or not. Also, no effect of the paramagnetic oxygen admixture enhancing OPR relaxation was observed.
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Affiliation(s)
- Robert Georges
- Institut de Physique de Rennes, UMR6251, CNRS-Université de Rennes 1 , Campus de Beaulieu, 35042 Rennes, France
| | - Xavier Michaut
- Laboratoire d'Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères, Sorbonne Universities, UPMC Univ. Paris 06, Université de Cergy-Pontoise, Observatoire de Paris, PSL Research University, CNRS , F-75252 Paris, France
| | - Audrey Moudens
- Laboratoire d'Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères, Sorbonne Universities, UPMC Univ. Paris 06, Université de Cergy-Pontoise, Observatoire de Paris, PSL Research University, CNRS , F-75252 Paris, France
| | - Manuel Goubet
- Université Lille, CNRS, UMR8523-PhLAM - Physique des Lasers, Atomes et Molécules , F-59000 Lille, France
| | - Olivier Pirali
- AILES beamline, Synchrotron SOLEIL, L'Orme des Merisiers , Saint Aubin BP 48, F-91192 Gif-sur-Yvette Cedex, France.,Institut des Sciences Moléculaires d'Orsay (ISMO), UMR 8214 CNRS, Univ. Paris-Sud, Université Paris-Saclay , F-91405 Orsay, France
| | - Pascale Soulard
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8233, MONARIS , F-75005 Paris, France
| | - Pierre Asselin
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8233, MONARIS , F-75005 Paris, France
| | - Thérèse Huet
- Université Lille, CNRS, UMR8523-PhLAM - Physique des Lasers, Atomes et Molécules , F-59000 Lille, France
| | - Pascale Roy
- AILES beamline, Synchrotron SOLEIL, L'Orme des Merisiers , Saint Aubin BP 48, F-91192 Gif-sur-Yvette Cedex, France
| | - Martin Fournier
- Institut de Physique de Rennes, UMR6251, CNRS-Université de Rennes 1 , Campus de Beaulieu, 35042 Rennes, France
| | - Andrey Vigasin
- Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences , 3 Pyzhevsky per, 119017 Moscow, Russia
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4
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Potapov A, Canosa A, Jiménez E, Rowe B. Chemie mit Überschall: 30 Jahre astrochemische Forschung und künftige Herausforderungen. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201611240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Alexey Potapov
- Laborastrophysikgruppe des Max-Planck-Instituts für Astronomie am Institut für Festkörperphysik; Friedrich-Schiller-Universität Jena; Helmholtzweg 3 07743 Jena Deutschland
| | - André Canosa
- Département de Physique Moléculaire; Institut de Physique de Rennes, UMR CNRS-UR1 6251, Université de Rennes 1, Campus de Beaulieu; 263 Avenue du Général Leclerc 35042 Rennes Cedex Frankreich
| | - Elena Jiménez
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas; Universidad de Castilla-La Mancha; Avda. Camilo José Cela, 1B 13071 Ciudad Real Spanien
| | - Bertrand Rowe
- Rowe-consulting, 22 Chemin des Moines; 22750 Saint Jacut de la Mer Frankreich
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Potapov A, Canosa A, Jiménez E, Rowe B. Uniform Supersonic Chemical Reactors: 30 Years of Astrochemical History and Future Challenges. Angew Chem Int Ed Engl 2017; 56:8618-8640. [DOI: 10.1002/anie.201611240] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 01/27/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Alexey Potapov
- Laborastrophysikgruppe des Max-Planck-Instituts für Astronomie am Institut für Festkörperphysik; Friedrich-Schiller-Universität Jena; Helmholtzweg 3 07743 Jena Germany
| | - André Canosa
- Département de Physique Moléculaire; Institut de Physique de Rennes, UMR CNRS-UR1 6251, Université de Rennes 1, Campus de Beaulieu; 263 Avenue du Général Leclerc 35042 Rennes Cedex France
| | - Elena Jiménez
- Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas; Universidad de Castilla-La Mancha; Avda. Camilo José Cela, 1B 13071 Ciudad Real Spain
| | - Bertrand Rowe
- Rowe-consulting, 22 Chemin des Moines; 22750 Saint Jacut de la Mer France
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6
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Structural and spectroscopic studies of carbon dioxide clusters: a combined genetic algorithm and DFT based study. Struct Chem 2013. [DOI: 10.1007/s11224-013-0360-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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7
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Christen W. Ultra-precise particle velocities in pulsed supersonic beams. J Chem Phys 2013; 139:024202. [DOI: 10.1063/1.4812371] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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8
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Crystallization of amorphous lactose at high humidity studied by terahertz time domain spectroscopy. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2012.12.044] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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9
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Suhm MA, Kollipost F. Femtisecond single-mole infrared spectroscopy of molecular clusters. Phys Chem Chem Phys 2013; 15:10702-21. [DOI: 10.1039/c3cp51515j] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Yeole SD, Sahu N, Gadre SR. Structures, energetics and vibrational spectra of CO2 clusters through molecular tailoring and cluster building algorithm. Phys Chem Chem Phys 2012; 14:7718-23. [DOI: 10.1039/c2cp23761j] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Harnes J, Winkler M, Lindblad A, Sæthre LJ, Børve KJ. Size of Free Neutral CO2 Clusters from Carbon 1s Ionization Energies. J Phys Chem A 2011; 115:10408-15. [DOI: 10.1021/jp206329m] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J. Harnes
- Department of Chemistry, University of Bergen, NO-5007 Bergen, Norway
| | - M. Winkler
- Department of Chemistry, University of Bergen, NO-5007 Bergen, Norway
| | - A. Lindblad
- Department of Materials’ Chemistry, Uppsala University, Box 538, SE-751 21 Uppsala, Sweden
| | - L. J. Sæthre
- Department of Chemistry, University of Bergen, NO-5007 Bergen, Norway
| | - K. J. Børve
- Department of Chemistry, University of Bergen, NO-5007 Bergen, Norway
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12
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Kumar R, Li Z, van Duin A, Levin D. Molecular dynamics studies to understand the mechanism of heat accommodation in homogeneous condensing flow of carbon dioxide. J Chem Phys 2011; 135:064503. [PMID: 21842939 DOI: 10.1063/1.3624335] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Using molecular dynamics (MD), we have studied the mechanism of heat accommodation between carbon dioxide clusters and monomers for temperatures and cluster size conditions that exist in homogeneous condensing supersonic expansion plumes. The work was motivated by our meso-scale direct simulation Monte Carlo and Bhatnagar-Gross-Krook based condensation simulations where we found that the heat accommodation model plays a key role in the near-field of the nozzle expansion particularly as the degree of condensation increases [R. Kumar, Z. Li, and D. Levin, Phys. Fluids 23, 052001 (2011)]. The heat released by nucleation and condensation and the heat removed by cluster evaporation can be transferred or removed from either the kinetic or translational modes of the carbon dioxide monomers. The molecular dynamics results show that the time required for gas-cluster interactions to establish an equilibrium from an initial state of non-equilibrium is less than the time step used in meso-scale analyses [R. Kumar, Z. Li, and D. Levin, Phys. Fluids 23, 052001 (2011)]. Therefore, the good agreement obtained between the measured cluster and gas number density and gas temperature profiles with the meso-scale modeling using the second energy exchange mechanism is not fortuitous but is physically based. Our MD simulations also showed that a dynamic equilibrium is established by the gas-cluster interactions in which condensation and evaporation processes take place constantly to and from a cluster.
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Affiliation(s)
- Rakesh Kumar
- The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
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Norooz Oliaee J, Dehghany M, McKellar ARW, Moazzen-Ahmadi N. High resolution infrared spectroscopy of carbon dioxide clusters up to (CO2)13. J Chem Phys 2011; 135:044315. [PMID: 21806127 PMCID: PMC3160451 DOI: 10.1063/1.3615543] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 06/30/2011] [Indexed: 11/15/2022] Open
Abstract
Thirteen specific infrared bands in the 2350 cm(-1) region are assigned to carbon dioxide clusters, (CO(2))(N), with N = 6, 7, 9, 10, 11, 12 and 13. The spectra are observed in direct absorption using a tuneable infrared laser to probe a pulsed supersonic jet expansion of a dilute mixture of CO(2) in He carrier gas. Assignments are aided by cluster structure calculations made using two reliable CO(2) intermolecular potential functions. For (CO(2))(6), two highly symmetric isomers are observed, one with S(6) symmetry (probably the more stable form), and the other with S(4) symmetry. (CO(2))(13) is also symmetric (S(6)), but the remaining clusters are asymmetric tops with no symmetry elements. The observed rotational constants tend to be slightly (≈2%) smaller than those from the predicted structures. The bands have increasing vibrational blueshifts with increasing cluster size, similar to those predicted by the resonant dipole-dipole interaction model but significantly larger in magnitude.
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Affiliation(s)
- J Norooz Oliaee
- Department of Physics and Astronomy, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4, Canada
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Oliaee JN, Dehghany M, Moazzen-Ahmadi N, McKellar ARW. Spectroscopic identification of carbon dioxide clusters: (CO2)6 to (CO2)13. Phys Chem Chem Phys 2010; 13:1297-300. [PMID: 21170441 DOI: 10.1039/c0cp02311f] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In spite of wide interest in CO(2) clusters, only dimers and trimers have previously been assigned to specific infrared bands. Here, transitions for clusters with 6-13 molecules are identified in the ν(3) region (∼2350 cm(-1)). Spectra are observed in a supersonic jet (T ∼ 2.5 K) using a tunable laser probe, and analyzed with the aid of cluster calculations based on a widely-used model potential. Vibrational origins show blue-shifts significantly larger than predicted by resonant dipole interactions.
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Affiliation(s)
- J Norooz Oliaee
- Department of Physics and Astronomy, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4, Canada
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15
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Dehghany M, McKellar A, Afshari M, Moazzen-Ahmadi N. High-resolution infrared spectroscopy of carbon dioxide dimers, trimers, and larger clusters. Mol Phys 2010. [DOI: 10.1080/00268976.2010.496742] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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16
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Sigurbjörnsson ÓF, Firanescu G, Signorell R. Intrinsic Particle Properties from Vibrational Spectra of Aerosols. Annu Rev Phys Chem 2009; 60:127-46. [DOI: 10.1146/annurev.physchem.040808.090356] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The spectroscopy of aerosols is developing into an active and important field. It allows us to characterize aerosols in a nonintrusive way, in real time, and on site. Understanding the spectroscopic features of these highly complex systems requires the development of novel experimental as well as theoretical methods. This review focuses on infrared extinction spectra. The main goal is to summarize how information about intrinsic particle properties (such as size, shape, and architecture) can be gathered from observed spectroscopic patterns. We discuss the limitations of standard continuum approaches, which have been used for decades to analyze infrared spectra, and we demonstrate the importance of molecular models for the analysis of spectroscopic data.
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Affiliation(s)
| | - George Firanescu
- Department of Chemistry, University of British Columbia, Vancouver V6T 1Z1, Canada
| | - Ruth Signorell
- Department of Chemistry, University of British Columbia, Vancouver V6T 1Z1, Canada
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17
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Devlin JP, Yinnon CA, Buch V. Spectroscopic evidence for cyclical aggregation and coalescence of molecular aerosol particles. Phys Chem Chem Phys 2009; 11:7819-25. [DOI: 10.1039/b905018n] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Jose KVJ, Gadre SR. An ab initio investigation on (CO2)n and CO2(Ar)m clusters: geometries and IR spectra. J Chem Phys 2008; 128:124310. [PMID: 18376922 DOI: 10.1063/1.2838202] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
An ab initio investigation on CO(2) homoclusters is done at MPWB1K6-31++G(2d) level of theory. Electrostatic guidelines are found to be useful for generating initial structures of (CO(2))(n) clusters. The ab initio minimum energy geometries of (CO(2))(n) with n=2-8 are T shaped, cyclic, trigonal pyramidal, tetragonal pyramidal, tetragonal bipyramidal, pentagonal bipyramidal, and pentagonal bipyramid with one CO(2) molecule attached to it. A test calculation on (CO(2))(20) cluster is also reported. The geometric parameters of the energetically most favored (CO(2))(n) clusters match quite well their experimental counterparts (wherever available) as well as those derived from molecular dynamics studies. The effect of clustering is quantified through the asymmetric C-O stretching frequency shift relative to the single CO(2) molecule. (CO(2))(n) clusters show an increasing blueshift from 1.8 to 9.6 cm(-1) on increasing number of CO(2) molecules from n=2 to 8. The energetics and geometries of CO(2)(Ar)(m) clusters have also been explored at the same level of theory. The geometries for m=1-6 show a predominant T type of the argon-CO(2) molecule interaction. Higher clusters with m=7-12 show that the argon atoms cluster around the oxygen atom after the saturation of the central carbon atom. The CO(2)(Ar)(m) clusters exhibit an increasing redshift in the C-O asymmetric stretch relative to CO(2) molecule of 0.7-5.6 cm(-1) with increasing number of argon atoms through m=1-8.
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Affiliation(s)
- K V Jovan Jose
- Department of Chemistry, University of Pune, Ganeshkhind 411007, India
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19
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Heinbuch S, Dong F, Rocca JJ, Bernstein ER. Single photon ionization of van der Waals clusters with a soft x-ray laser: (CO2)n and (CO2)n(H2O)m. J Chem Phys 2007; 125:154316. [PMID: 17059264 DOI: 10.1063/1.2348877] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Pure neutral (CO2)n clusters and mixed (CO2)n(H2O)m clusters are investigated employing time of flight mass spectroscopy and single photon ionization at 26.5 eV. The distribution of pure (CO2)n clusters decreases roughly exponentially with increasing cluster size. During the ionization process, neutral clusters suffer little fragmentation because almost all excess cluster energy above the vertical ionization energy is taken away by the photoelectron and only a small part of the photon energy is deposited into the (CO2)n cluster. Metastable dissociation rate constants of (CO2)n+ are measured in the range of (0.2-1.5) x 10(4) s(-1) for cluster sizes of 5< or =n< or =16. Mixed CO2-H2O clusters are studied under different generation conditions (5% and 20% CO2 partial pressures and high and low expansion pressures). At high CO2 concentration, predominant signals in the mass spectrum are the (CO2)n+ cluster ions. The unprotonated cluster ion series (CO2)nH2O+ and (CO2)n(H2O)2+ are also observed under these conditions. At low CO2 concentration, protonated cluster ions (H2O)nH+ are the dominant signals, and the protonated CO2(H2O)nH+ and unprotonated (H2O)n+ and (CO2)(H2O)n+ cluster ion series are also observed. The mechanisms and dynamics of the formation of these neutral and ionic clusters are discussed.
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Affiliation(s)
- S Heinbuch
- Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523, USA
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Böyükata M, Borges E, Belchior JC, Braga JP. Structures and energetics of CO2–Arn clusters (n = 1–21) based on a non-rigid potential model. CAN J CHEM 2007. [DOI: 10.1139/v06-178] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Energetics and possible stable structures of CO2–Arn (n = 1–21) clusters are investigated by performing molecular-dynamics simulations. The pairwise-additive approximation is tested to construct the potential energy function for describing the non-rigid particle interactions in the system. A potential model by Pariseau et al. (Journal of Chemical Physics, Vol. 42, p. 2335, 1965) is used for the internal motion of the CO2 molecule and the Billing form potential (Chemical Physics, Vol. 185, p. 199, 1994) is used for all other pair interactions. The stable configurations are determined for the ground state of CO2–Arn clusters, and the growing pattern process of the clusters is determined via rearrangement collisions. Ar atoms tend to surround the CO2 molecule, and the clusters prefer to form three-dimensional compact structures. Obtained structures and energetics are in quantitative agreement with previous results (Journal of Chemical Physics, Vol. 109, p. 1343, 1998) that have used split-repulsion and ab initio potentials in which the molecule was treated as rigid.Key words: argon, CO2, cluster, potential energy function, molecular dynamics.
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Walker NR, Walters RS, Duncan MA. Infrared photodissociation spectroscopy of V+(CO2)n and V+(CO2)nAr complexes. J Chem Phys 2006; 120:10037-45. [PMID: 15268025 DOI: 10.1063/1.1730217] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
V+(CO2)n and V+(CO2)nAr complexes are generated by laser vaporization in a pulsed supersonic expansion. The complexes are mass-selected within a reflectron time-of-flight mass spectrometer and studied by infrared resonance-enhanced (IR-REPD) photodissociation spectroscopy. Photofragmentation proceeds exclusively through loss of intact CO2 molecules from V+(CO2)n complexes or by elimination of Ar from V+(CO2)nAr mixed complexes. Vibrational resonances are identified and assigned in the region of the asymmetric stretch of free CO2 at 2349 cm(-1). A linear geometry is confirmed for V+(CO2). Small complexes have resonances that are blueshifted from the asymmetric stretch of free CO2, consistent with structures in which all ligands are bound directly to the metal ion. Fragmentation of the larger clusters terminates at the size of n=4, and a new vibrational band at 2350 cm(-1) assigned to external ligands is observed for V+(CO2)5 and larger cluster sizes. These combined observations indicate that the coordination number for CO2 molecules around V+ is exactly four. Fourfold coordination contrasts with that seen in condensed phase complexes, where a coordination number of six is typical for V+. The spectra of larger complexes provide evidence for an intracluster insertion reaction that produces a metal oxide-carbonyl species.
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Affiliation(s)
- N R Walker
- Department of Chemistry, University of Georgia, Athens, GA 30602-2556, USA
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Firanescu G, Hermsdorf D, Ueberschaer R, Signorell R. Large molecular aggregates: From atmospheric aerosols to drug nanoparticles. Phys Chem Chem Phys 2006; 8:4149-65. [PMID: 16971983 DOI: 10.1039/b608433h] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Large molecular aggregates with sizes ranging from subnanometers to microns are ubiquitous. As atmospheric aerosols they influence our climate, in interstellar space they are discussed as reactive sites, and in medicine small particles are considered as promising candidates to achieve a targeted drug delivery. The present contribution is focused on the characterization of the physical-chemical properties of these particles and on their targeted generation. One of the greatest challenges is to understand the properties of these aggregates on a molecular level. The latter point is discussed in detail focussing on the vibrational dynamics of these particles.
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Affiliation(s)
- George Firanescu
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1
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23
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Signorell R, Jetzki M, Kunzmann M, Ueberschaer R. Unraveling the Origin of Band Shapes in Infrared Spectra of N2O−12CO2 and 12CO2−13CO2 Ice Particles. J Phys Chem A 2005; 110:2890-7. [PMID: 16509610 DOI: 10.1021/jp053021u] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Band structures in the region of strong infrared absorption bands for different N2O-12CO2 and 12CO2-13CO2 composite particles are investigated by combining quantum mechanical exciton calculations with systematic experimental investigations. The ice particles are generated by collisional cooling and characterized with rapid-scan infrared spectroscopy. The size of the particles lies between approximately 10 and 100 nm. The calculated spectra show excellent agreement with the experimental data. This work leads to a detailed understanding on a molecular level of shape effects in pure and statistically mixed particles as well as of the characteristic features observed for core-shell particles.
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Affiliation(s)
- Ruth Signorell
- Institut für Physikalische Chemie, Universität Göttingen, Tammannstrasse 6, D-37077 Göttingen, Germany.
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Taraschewski M, Cammenga HK, Tuckermann R, Bauerecker S. FTIR Study of CO2 and H2O/CO2 Nanoparticles and Their Temporal Evolution at 80 K. J Phys Chem A 2005; 109:3337-43. [PMID: 16833668 DOI: 10.1021/jp044075r] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fourier transform infrared (FTIR) spectroscopy combined with a long-path collisional cooling cell was used to investigate the temporal evolution of CO2 nanoparticles and binary H2O/CO2 nanocomposites in the aerosol phase at 80 K. The experimental conditions for the formation of different CO2 particle shapes as slab, shell, sphere, cube, and needle have been studied by comparison with calculated data from the literature. The H2O/CO2 nanoparticles were generated with a newly developed multiple-pulse injection technique and with the simpler flow-in technique. The carbon dioxide nu3-vibration band at 2360 cm(-1) and the water ice OH-dangling band at 3700 cm(-1) were used to study the evolution of structure, shape, and contact area of the nanocomposites over 150 s. Different stages of binary nanocomposites with primary water ice cores were identified dependent on the injected CO2 portion: (a) disordered (amorphous) CO2 slabs on water particle surfaces, (b) globular crystalline CO2 humps sticking on the water cores, and (c) water cores being completely enclosed in bigger predominantly crystalline CO2 nanoparticles. However, regular CO2 shell structures on primary water particles showing both longitudinal (LO) and transverse (TO) optical mode features of the nu3-vibration band could not be observed. Experiments with reversed nucleation order indicate that H2O/CO2 composite particles with different initial structures evolve toward similar molecular nanocomposites with separated CO2 and H2O regions.
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Affiliation(s)
- M Taraschewski
- Institut für Physikalische und Theoretische Chemie, Technische Universität Braunschweig, Hans-Sommer-Strasse 10, D-38106 Braunschweig, Germany
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Buch * V, Sigurd B, Paul Devlin J, Buck U, Kazimirski JK. Solid water clusters in the size range of tens–thousands of H2O: a combined computational/spectroscopic outlook. INT REV PHYS CHEM 2004. [DOI: 10.1080/01442350412331316124] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Jaeger JB, Jaeger TD, Brinkmann NR, Schaefer HF, Duncan MA. Infrared photodissociation spectroscopy of Si+(CO2)n and Si+(CO2)nAr complexes Evidence for unanticipated intracluster reactions. CAN J CHEM 2004. [DOI: 10.1139/v04-044] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Si+(CO2)n and Si+(CO2)nAr ionmolecule complexes were produced by laser vaporization in a pulsed supersonic expansion. The ions were mass-selected in a reflectron time-of-flight spectrometer and studied with infrared photodissociation spectroscopy near the asymmetric stretch vibration of CO2. Si+(CO2)n clusters fragment by the loss of CO2 whereas Si+(CO2)nAr complexes fragment by the loss of argon. All clusters have resonances near the CO2 asymmetric stretch, but with shifts in frequency that are size dependent. The patterns seen in the small clusters are consistent with electrostatic bonding, while the larger systems provide evidence for an intracluster reaction forming oxide-carbonyl species. Density functional theory was employed to examine the structures of these clusters, and their calculated vibrational frequencies were compared to the measured values. Ligand assembly in Si+(CO2)n complexes is dominated by the presence of the occupied 3p valence orbital of the silicon cation. Key words: ionmolecule complexes, infrared spectroscopy, photodissociation, density functional theory.
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Walters RS, Brinkmann NR, Schaefer HF, Duncan MA. Infrared Photodissociation Spectroscopy of Mass-Selected Al+(CO2)n and Al+(CO2)nAr Clusters. J Phys Chem A 2003. [DOI: 10.1021/jp030491k] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- R. S. Walters
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - N. R. Brinkmann
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - H. F. Schaefer
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - M. A. Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
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